Open 'em all*; let votes sort 'em out.
*except for things that are actually off-topic or out of scope
Originally, we closed such questions as "General Reference", but we had a problem where we could never totally agree on what constituted "General Reference". Almost any question can be answered via Google in just one search of the correct keywords. Closing every question that could be "easily" Googled would close more questions than we wanted.
Additionally, we decided that one does not need to have read/watched the work being asked about, meaning that even the most trivial and obvious of questions about a work are on topic
Over time, we realized that we never really had a problem with having too many "too easy" questions (they certainly show up, but they don't overrun the site). This led to us burninating General Reference.
When the question came up again later, we reiterated that we do not close questions for being "too trivial".
Beofett's answer still reflects the general consensus:
Why is it not sufficient to say "if a question is trivial, boring, and demonstrates little to no research, downvote it"? Note that the hover-text for downvoting states quite clearly that a question or answer should be downvoted when it "does not show any research effort" or "it is unclear or not useful"!
As for why such questions are upvoted, well, that's every user's prerogative. They may find the question interesting, or useful, or they may have just wondered about the same thing. You may not, and that's OK. Vote however you want (so long as it's on the post, not the poster), and everyone else will do the same. Typically, the votes will eventually reflect the overall quality of the question (except for questions which hit the Hot Network Questions List, which can dramatically skew scores.)